Plant Pathology - Study Mode
[#466] Tobacco root exudates contains which chemical substances during induction of chemtotaxis against A. tumefaciens?
Correct Answer
(B) Acetosyringone
Explanation
Solution: Tobacco root exudates contain Acetosyringone chemical substances during induction of chemotaxis against A. tumefaciens. Agrobacterium tumefaciens is a soil phytopathogen that naturally infects plant wound sites and causes crown gall disease via delivery of transferred (T)-DNA from bacterial cells into host plant cells through a bacterial type IV secretion system. Acetosyringone is known to improve transformation efficiency by up-regulating the virulence of Agrobacterium. In previous studies using Eustoma, the effect of this compound has only been tested during inoculation.
[#467] The leaves of Pongamia glabra and Azadirachta indica reduces the population of
Correct Answer
(A) Root-knot nematode
Explanation
Solution: The leaves of Pongamia glabra and Azadirachta indica reduce the population of Root-knot nematode. Root-knot nematode larvae infect plant roots, causing the development of root-knot galls that drain the plant's photosynthetic and nutrients. Infection of young plants may be lethal, while infection of mature plants causes decreased yield. To kill nematodes in soil, heat small quantities of moist soil to 140°F in the oven or by solarization. The leaves of the above specific trees also reduce the population of nematodes.
[#468] Photosynthetic pigments found in the chloroplasts occurs in
Correct Answer
(A) Thylakoid membranes
Explanation
Solution: Photosynthetic pigments found in the chloroplasts occur in Thylakoid membranes. Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen. The thylakoid membrane is the site of the light-dependent reactions of photosynthesis with the photosynthetic pigments embedded directly in the membrane. It is an alternating pattern of dark and light bands measuring each 1 nanometre.
[#469] Which one is diploid?
Correct Answer
(B) Secondary nucleus
Explanation
Solution: The secondary nucleus is diploid. The secondary (definitive) nucleus is formed by the fusion of two haploid polar nuclei hence it is diploid (2n). It is also called the primitive endosperm nucleus. It is the main food source for angiosperm embryos.
[#470] White blisters of crucifers' is caused by pathogen
Correct Answer
(B) Albugo candida
Explanation
Solution: White blisters of crucifers' is caused by the pathogen Albugo candida. A. candida is an obligate plant pathogen that infects Brassicaceae species and causes the disease known as white rust or white blister rust. It has a relatively smaller genome than other oomycetes. White rust, also called white blisters, is a fungal disease caused by the fungus Albugo candida, which affects cruciferous plants that include vegetables such as kale, Brussels sprouts, cauliflower, broccoli and cabbage.